Fungal bioleaching of WPCBs using Aspergillus niger: Observation, optimization and kinetics.

In this study, Aspergillus niger (A. niger) as an environmentally friendly agent for fungal bioleaching of waste printed circuit boards (WPCBs) was employed. D-optimal response surface methodology (RSM) was utilized for optimization of the bioleaching parameters including bioleaching method (one step, two step and spent medium) and pulp densities (0.